First you must start off with knowledge and helpful wisdom… It just so happens that you will find both here.
Either purchase and use “7 way test strips” or take a water bottle with a sample of the pool water down to your local pool supply store and have them analyze it for you, they will do this for free. Ask them to perform and print a full spectrum analysis: Total Chlorine, Free chlorine, pH, alkalinity, Calcium hardness, total dissolved solids, cyanuric acid, water metals (manganese, copper, iron, etc), nitrite/nitrate, and phosphates.
Once you get the sample results and “recommendations” send them to me via email. Remember to include the material the swimming pool surface is made of (plaster or vinyl), the gallon size of the pool, filtration system if you know the specs, chlorination system (hopefully it’s a chlorine pool or a Bromine pool….) and any chemicals the “previous owner” may have left for you.
With this info and a few moments we can set you up on a full maintenance schedule to keep your water crystal clear and also take you step by step through the various chemicals, uses, and levels of maintenance. Plus help you clean up the green water you have now.
All for free.